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NOAA Joint OSSE System’s Applications for WISDOM project. Y. Zhang, Y . Xie , N. Prive , and B. Mock Jan 18, 2012 GSD/FAB. Outline. Introduction of WISDOM OSSE; Necessary elements; Selection of launch sites (forward and reverse runs); Generating synthetic WISDOM balloon data;
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NOAA Joint OSSE System’s Applications for WISDOM project Y. Zhang, Y. Xie, N. Prive, and B. Mock Jan 18, 2012 GSD/FAB
Outline • Introduction of WISDOM OSSE; • Necessary elements; • Selection of launch sites (forward and reverse runs); • Generating synthetic WISDOM balloon data; • GSI data assimilation (WISDOM data treated as sonde data); • Results; • Conclusions and future works.
What is an OSSE? An OSSE is a modeling experiment used to evaluate the impact of new observing systems on operational forecasts when actual observational data is not available. Nature run (“truth”): A long model run Synthetic observation: from the nature run Forecast: A second model
NOAA Joint OSSE System • Nature Run: ECMWF operational model, • T511/91L resolution • 13 month free integration, 01 May 2005 - 31 May 2006 • 13 Atlantic basin tropical cyclones which show sufficiently realistic track behavior • Forecast Model: GSI/GFS • early 2007 NCEP operational version and updated to 2010 • T384/64L resolution • 120 hour forecasts at 00Z and 12Z
Why a WISDOM OSSE? • WISDOM data impact on hurricane track? • Cost benefit evaluation for NOAA WISDOM program; • Design for WISDOM launch strategy: Such as: balloon launch sites; drift height etc.
WISDOM Experiments • Initial case study focused on track forecasts for AL01 • Forward experiments: Impact of WISDOM balloon data on hurricane track forecasts
Forward Experiments • Prepare the Synthetic WISDOM balloon data: Generate from nature run. • The forecast: GSI/GFS Control run(without wisdom data) Simulation run(with wisdom data) • The nature run: ECMWF operational model
Prepare the synthetic WISDOM data • Used to use the Matlab takes several days to get the data. • Use the Fortran to get the synthetic data. It only takes several hours to get all the WISDOM synthetic data.
Prepare the synthetic WISDOM data • Generate the synthetic WISDOM data from the nature run: -Set up the balloon launch strategy: launch sites; launch time; the frequency of data output; drift height. -Get the data from the nature run at the each data output time of each balloon -Output the formatted WISDOM data
Prepare the synthetic WISDOM data • Read the nature run’s data at ti /ti+dt. • Then loop over from ti to ti+dt: • Check the balloon status at ti+dmin: not launched yet/need to be launched/still flying/dead • Get the location of the flying/launched balloon Use the u/v and w to calculate the new longitude/latitude and height • Do the interpolation at the balloon location Use the nearby grid(12 points) to do the interpolation • Output the data at each output time
Synthetic WISDOM data • WISDOM balloon launch sites: The blue points is the WISDOM balloon launch sites. 111 launch sites
Synthetic WISDOM data • WISDOM balloon track: • Twice a day: • 1th/Aug ~ 5th/Aug • Get the WISDOM data: • Every 30 minutes • Two levels • Drift height: • 3650m/8000m Balloon numbers: 5*2*2*111=2220 Total data : 427,128
The synthetic WISDOM data The formatted synthetic WISDOM data: ……………………….. 990 08 05 09 0 335.3394 15.1681 3650.0000 661.8108 280.5027 0.0046 -13.1778 2.2225 991 08 05 09 0 335.3278 15.1780 3650.0000 661.8168 280.5037 0.0046 -13.1868 2.2165 992 08 05 09 0 334.9585 15.4309 3650.0000 661.9054 280.4928 0.0046 -14.0591 1.8207 993 08 05 09 0 346.2748 9.0562 3650.0000 660.6028 278.1284 0.0062 -1.1717 -5.5093 994 08 05 09 0 346.6964 8.0057 3650.0000 660.5472 278.2640 0.0059 -1.4318 -5.4787 995 08 05 09 0 343.8452 28.2141 3650.0000 662.8626 284.2172 0.0051 0.8184 -0.6793 996 08 05 09 0 343.0198 17.2972 3650.0000 662.4750 282.2396 0.0063 -12.2012 -7.1161 997 08 05 09 0 341.7729 14.2278 3650.0000 661.7869 280.2286 0.0063 -11.1233 -5.1319 998 08 05 09 0 342.2312 14.2233 3650.0000 661.7036 280.3158 0.0063 -10.2152 -6.4130 999 08 05 09 0 342.6686 15.3252 3650.0000 661.9710 281.0749 0.0063 -11.2500 -6.7864 1111 08 05 09 0 279.6201 39.7949 8000.0000 370.0029 244.8437 0.0007 23.7174 -9.1831 1112 08 05 09 0 246.9378 14.3139 8000.0000 378.7501 253.7333 0.0008 -4.4780 -0.4843 1113 08 05 09 0 273.8472 45.8047 8000.0000 366.9842 241.9702 0.0002 19.3304 -22.2680 1114 08 05 09 0 314.7721 82.3237 8000.0000 357.3938 237.7147 0.0002 7.4927 -6.5102 1115 08 05 09 0 307.3623 57.7163 8000.0000 361.2642 239.1260 0.0002 2.5476 12.1774 1116 08 05 09 0 294.2139 50.2862 8000.0000 359.8100 238.5330 0.0002 16.0568 11.8093 1117 08 05 09 0 283.7850 42.1108 8000.0000 365.4696 241.0415 0.0007 19.0525 1.3713 1118 08 05 09 0 291.1477 77.4562 8000.0000 362.0339 239.3750 0.0001 8.9179 -6.8950 1119 08 05 09 0 282.7004 79.8352 8000.0000 359.1806 238.9504 0.0001 19.4687 11.0594 ……………………….. Id m d h m lonlat height pre temp hum u v
Check the WISDOM synthetic data The temperature of nature run and synthetic WISDOM data at 06 Aug 00Z The left nature run. The right one is the synthetic WISDOM data Shadow areas are the temperature; Grey points is the balloon location at that time The height of 710hPa is 3450 to 3850.
Check the WISDOM synthetic data The q and wind of nature run and synthetic WISDOM data at 06 Aug 00Z The left nature run. The right one is the synthetic WISDOM data Shadow areas are the q (mg/kg); black points is the balloon location at that time
Design of the control and simulation runs • The common of GSI/GFS between the control and simulation runs: -Get the initial field at 1 Aug 00Z -Assimilate the RAOB, AMSU-A, ACAR, AIRS GOES data to get the analysis field. -Use GFS to get the forecast: 120h forecast at every 6h interval from 1 Aug 06Z to 7Aug 12Z • The difference of GSI/GFS between the control and simulation runs: -Simulation run assimilates the WISDOM data.
Design of the control and simulation runs wisdom data from 080103 to 080109 120h forecast GFS analysis field for GFS: 2005080106 background for GSI: 2005080112 initial field time 2005080100 GFS background for GSI: 2005080106 GSI 120h forecast GSI GSI GFS background for GSI: 2005080200 2005080712’s 120h forecast analysis field for GFS: 2005080112 GFS wisdom data from 080109 to 080115
Prepare the WISDOM data for GSI • GSI only taken the BUFR format data -Need to convert the WISDOM format data into WISDOM BUFR format. Synthetic WISDOM data BUFR format
Validation of WISDOM Data Ingest The analysis field’s 710hPa/500hPa height at 6 Aug 00Z.( s_run/c_run/n_run)
Balloon location and forecast track Balloon location and forecast track for the 6 Aug 00Z The number of balloon data: 21312
Impact of WISDOM on Track The impact of WISDOM data on hurricane track forecast at different forecast time
Forecast errors (km) Red = improvement Black = worsening
Discussion • The large numbers of WISDOM synthetic data do not have a significance impact on trajectory forecast in this experiments: a. The improvement of trajectory forecast errors are limited b. The simulation run have a better trajectory pattern.
Future Work • Use another control run which has a closer hurricane location or uses a relocation method. • Add observation errors into the synthetic WISDOM data • Use adaptive method(ETKF) to design WISDOM launch strategy over targeted observation areas. For ETKF: Need to get some ensemble forecast first.